Means for supporting resistance elements



3 G H WHITTINGHAM 5 BANS FOR SUPPORTING RESISTANCE ELEIENTS Filed July 23, 1926 2 Sheets-Sheet 1 Feb. 3, 1931. s. H. WHITTINGHAM "BANS FOR SUPPORTING RESISTANCE ELEIENTS Filed July 25, 1926 2 Shaw-Sheet 2 alto "aw Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE GEORGE E. WHITTINGHAM, OF BALTIMORE, MARYLAND, ASSIGNOR TO MONITOR CON- TBOLLER COMPANY, 01' BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND MEANS FOR SUPPORTING RESISTANCE ELEMENTS Application filed July 28,

This invention relates to means for mounting resistance coils on electrically driven vehicles. On electrically propelled railway cars iron grids are commonly employed as 6 resistance elements, and these are usually grouped somewhat closely together for con venience in connecting the grids. Because of this close grouping of the grids, the ventilation through the grids is poor and the 10 heat is concentrated in one place. The grids are more or less fragile and the vibration caused by the movement of the car sometimes causes them to break. Furthermore, theresistance of the iron in the rids varies with the temperature and this is undesirable in a motor controlling rheostat, as will be readily understood.

In carr ing out my invention, I substitute for tli e grids a coil, or coils, composed of flat resistance metal wound on edge and having practically no temperature coefiicient. This metal is ductile and cannot be injured by the vibration of the car, and the coils may be made as long as desired and extended lengthwise or crosswise of the car, insuring good ventilation. These coils are threaded on to .cores composed of relatively fiat pieces of insulating material and having teeth which space the convolutions of the coils apart, and the insulating material is mounted upon a metal bar which holds the pieces in alinement.

Instead of supporting the coil on its core, I provide a support consisting of 'a metal bar or strip attached at its ends to the car body and extending horizontally under the car floor, andthe connectors for the coil are dtachably secured to this bar and clamped directly to the convolutions of the coil. Thus, where it is desired to take off a ta from the coil, a connector will be clamped to the convolution of the coil, and a post, which forms a part of the connector, will be detachably secured to said bar, so that the connectors serve to directly support the coil and also as a means for electrically connecting it to the wire or cable terminals.

,In the accompanying drawing,

Fig. 1 is a side elevation of a resistor and its supporting means, partly broken away,

1926. Serial Io. 124,403.

the support being shown suspended from the cross timbers of a car floor;

Fig. 2 is a central longitudinal section through the left hand ends of the support and the resistor;

Fig. 3 is a section on the line 33 of Fig 1;

ig. 4 is a perspective view of the support shown in the previously described figures;

Fig. 5 is a side elevation of a resistor and a modified supporting member, partly broken away;

Fig. 6 is a central longitudinal section through the left hand end of the same; and,

Fig. 7 is a section on the line 7-7 of ent No. 1,550,640. A helix 5, composed of a I flat ribbon of resistance metal, wound on ed e, is threaded on to the covering, the convo utions of the helix being spaced apart by the teeth on the covering. In the patent referred to, the flat metal bar 2 has its ends extended beyond the coil or helix and this bar forms the supporting means for the coil and connectors which are attached to the coil. In the present invention, the resistor is supported by connectors d, each of which is clamped directly'to a convolution of the helix and the connectors are suspended from the supporting member a. As shown in Figs. 2 and 3, each connector comprises two flat clamping members 6 and 7, held together at their upper ends by a clamping screw 8. The lower portion of the member 7 has forked arms 7 curved to correspond to the curvature of the helix, and it has a central notch 7 adapted to fit over the upper edge of the insulated covering 3. The lower portion of the'member 6 is similarly formed and has tongues 6 which project through the convolution to which the connector is attached. These tongues serve to position theconnector with respect to the margins of the convolution, and the notches in the connector interlock 'with theinsulated covering and position the latter with respect to the connector. The connectors are substantially the same as those shown in my prior patent referred to, but instead of being supported by the helix, they serve in the present invention as a means for supporting the helix and its core. As shown, threaded posts 10 are secured to the clamping members 6 and 7 of each connector, and these posts extend through a slot 11 in the supporting member 0. This supporting member comprises a fiat sheet metal bar or plate 12, having the slot 11 extending longitudinally through its central portion and having downwardlyturned flanges 13 which strengthen the bar, and having its ends bent upwardly as shown at 14, and thence outwardly, as.

shown at 15. The end portions 15 are provided with screw holes 16, through which bolts 16 may be passed to attach the bar to the timbers of the car floor. The posts 10, which constitute parts of the connectors, are fitted with insulating washers 17 and 18, above and below the central part of the member 0, and nuts 19 and 20 on the posts clamp these washers tightly against the bar. The wire or cable terminals 21 are secured to the posts by the clamping nuts.

It will be evident that a terminal can be adjusted along the bar to any desired position and connected to any convolution of the helix, and when the clamping nuts are tightened, the connector will mechanically support the helix and its core and also connect the helix electrically with the terminal 21. As the helix consists of a metal ribbon wound on edge, its convolutions are very'rigid circumferentially, and as they are spaced apart by the teeth on the insulation of the core, the entire structure is rigid and will not become displaced or disarranged by the vibration of the car. The resistor may be arranged lengthwise or crosswise of the car, as may be found most convenient, and several resigtors may be grouped together when deslre In Figs. 5 to 7 inclusive, I have shown a modified form of support for the resistor, the latter being the sameas the resistor illustrated in the previously described figures. In Figs. 5 to 7, a round metal bar 22 is provided with tubular spacers 23, of insulating material, and between these spacers the connectors d are supported. Each connector d comprises the flat clamping members 6 and 7 the member 7 being continued above the member 6 to form a binding post 10. This post has a circular opening 24 and an insulating washer 25 on the rod or bar 22 has are shown with hooked ends 29*,

a. hub 25 which projects through said opening. An insulating washer 26 is arranged on the bar 22 on the opposite side of the post, and the post is clamped between said washers by clamping nuts 27, threaded on to the opposite ends of the bar. The various connectors are all suspended from the bar 22 in the same manner, and the nuts 27, when tightened, clamp all of the posts to the rod. As in the previously described figures, the connectors mechanically support the helix and its core and also form electrical connections to which the terminals of wires or cables may be attached. Thus, each of the binding posts has an opening 28 through which a screw may be inserted to connect a wire or cable terminal.

The supporting member 0 may be suspended from the under side of the earthy posts 29 rigidly secured to the car floor or its cross timbers. These posts in the drawing adapted to receive the ends of the member 0, and with clamping screws 30 for securing the member in the hooked portions of the posts.

What I claim is:

1. The combination with a supporting bar of a resistance element comprising a toothed core of insulating material and a helix of flat resistance metal wound on edge and threaded on to said core, and a plurality of connectors supporting said element, saidconnectors detachably connected to and insulated from said bar and the several connectors being clamped to separate convolutions of the helix, said connectors being adjustable along the bar so that any connector maybe clamped to any one of a plurality of convolutions.

2. The combination with a supporting bar adapted for connection to a vehicle body and having a longitudinal slot, of aresistance elementcomprising a toothed core of insulating material and a helix of flat resistance metal wound on edge and threaded on to said core, and a plurality of connectors clamped to separate convolutions of said helix and extending through said slot, said connectors being adjustable along the bar to engage any of the convolutions of the helix, and means for detachably securing the connectors to the bar.

In testimony whereof I hereunto afiix my signature.

GEORGE H. WHITTINGHAM. 

